This application relates generally to interconnection systems, such as those including electrical connectors, used to interconnect electronic assemblies.
Electrical connectors are used in many electronic systems. It is generally easier and more cost effective to manufacture a system as separate electronic assemblies, such as printed circuit boards (“PCBs”), which may be joined together with electrical connectors. A known arrangement for joining several PCBs is to have one PCB serve as a backplane. Other PCBs, called “daughterboards” or “daughtercards”, may be connected through the backplane.
A known backplane is a PCB onto which many connectors may be mounted. Conducting traces in the backplane may be electrically connected to signal conductors in the connectors so that signals may be routed between the connectors. Daughtercards may also have connectors mounted thereon. The connectors mounted on a daughtercard may be plugged into the connectors mounted on the backplane. In this way, signals may be routed among the daughtercards through the backplane.
Electrical connector designs have been adapted to mirror trends in the electronic industry. Electronic systems generally have gotten smaller, faster, and functionally more complex. Because of these changes, the number of circuits in a given area of an electronic system, along with the frequencies at which the circuits operate, have increased significantly in recent years. Current systems pass more data between PCBs and require electrical connectors that are electrically capable of handling more data at higher speeds than connectors of even a few years ago.
Electrical connectors typically include a dielectric connector housing supporting a plurality of electrical contacts. For example, electrical connectors can be constructed with arrays of electrical contacts having solder balls fused to mounting ends of the contacts. The mounting ends may be held in an array, creating a ball grid array (BGA) connector.
In a high density, high speed connector, electrical conductors may be so close to each other that there may be electrical interference between adjacent signal conductors. To reduce interference, and to otherwise provide desirable electrical properties, reference conductors are often placed between adjacent signal conductors.